1. Field of the Invention
The present invention relates to a reusable tool for making parts and a method of making reusable tooling for producing sand castings, sheet metal dies, and for producing vacuum formed parts.
2. Background Art
Prototype tooling is used for low volume production of prototypes. Prototype parts are manufactured to permit testing and evaluation of the prototype parts prior to releasing the part for manufacture. There is a need for reusable tooling for making prototypes if more than one prototype part is to be made. For some parts, twenty or more prototypes may be needed for evaluation and testing purposes. The per piece cost of prototype tooling is relatively expensive due to the low number of parts over which the cost of the tooling may be amortized. There is a need for reusable prototype tooling that can be manufactured without adding excessive costs to the prototype tooling.
Conventional prototype tooling for cope and drag dump boxes generally include a pattern that may be formed of wood or REN board that is cut or CNC machined to the desired pattern shape. The pattern is then assembled to a REN board box.
Recent developments relating to rapid casting technology have led to the development of sand and resin printing machines that can print a three-dimensional pattern by sequentially layering a sand and activator mixture and a printed resin according to CAD data for a prototype part. A pattern may be printed in this manner and assembled to a REN board box to form cope and drag dump boxes for making prototype parts. A problem with this approach is that substantial expense and delay are incurred relating to the assembly of the pattern to the separately fabricated REN board box.
The use of rapid casting technology to produce three-dimensional patterns is normally limited to a single use but in some cases the patterns may be used a few times. However, the patterns are not durable and may suffer from breakage or wear resulting in the loss of surface finish and dimensional accuracy if a rapid casting three-dimensional model is used multiple times.
There is a need for reusable prototype tooling such as cope and drag boxes that may be used in making prototype sand castings for foundries. Prototype sand castings may be made from sections of a mold that are assembled as a sand casting mold assembly for producing the prototype part.
There is a need for a more cost effective method of making a stamping die for stamping prototype parts in a fluid press.
There is also a need for more cost effective reusable tooling for making plastic parts in a vacuum forming process. For example, machined vacuum form tools are known to be used to manufacture plastic prototype trim parts such as lenses for lights. A reusable tool for making a vacuum formed plastic prototype part that does not require extensive machining or assembly to REN supporting structures is not known to be available in the prior art.
The above problems and needs are addressed by applicants' invention as summarized below.